Power control of neighbor discovery signals

ABSTRACT

A method of adjusting power of a neighbor discovery signal may include determining a maximum transmission power of a transmitting wireless device. The transmitting wireless device may be configured to transmit a neighbor discovery signal to one or more receiving wireless devices. The one or more receiving wireless devices may be discovered neighbor wireless devices of the transmitting wireless device and may be configured to receive the neighbor discovery signal. The method may further include determining a power level of the neighbor discovery signal based on the maximum transmission power of the transmitting wireless device and a number of the discovered neighbor wireless devices.

FIELD

The present disclosure relates to power control of neighbor discoverysignals.

BACKGROUND

The proliferation of smartphones, tablets, laptop computers and otherelectronic devices (referred to generally as “wireless devices”) thatuse wireless communication networks has created an increasing demand forubiquitous and continuous wireless voice and data access.Device-to-device (D2D) communication may help satisfy this demand. Forexample, D2D communication may be performed between wireless devices andmay allow the wireless devices to capture information and communicatethe information with each other. This D2D communication may allow forreuse of wireless communication resources, which may help satisfy thedemand for wireless voice and data access.

The subject matter claimed herein is not limited to embodiments thatsolve any disadvantages or that operate only in environments such asthose described above. Rather, this background is only provided toillustrate one example technology area where some embodiments describedherein may be practiced.

SUMMARY

According to an aspect of an embodiment, a method of adjusting power ofa neighbor discovery signal may include determining a maximumtransmission power of a transmitting wireless device. The transmittingwireless device may be configured to transmit a neighbor discoverysignal to one or more receiving wireless devices. The one or morereceiving wireless devices may be discovered neighbor wireless devicesof the transmitting wireless device and may be configured to receive theneighbor discovery signal. The method may further include determining apower level of the neighbor discovery signal based on the maximumtransmission power of the transmitting wireless device and a number ofthe discovered neighbor wireless devices.

The object and advantages of the embodiments will be realized andachieved at least by the elements, features, and combinationsparticularly pointed out in the claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and arenot restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be described and explained with additionalspecificity and detail through the use of the accompanying drawings inwhich:

FIG. 1 illustrates an example wireless communication network configuredto initiate device-to-device (D2D) communication between wirelessdevices;

FIG. 2 illustrates an example matrix depicting a configuration ofneighbor discovery channel resources;

FIGS. 3A and 3B illustrate example scheduling matrices depictingassignments of neighbor discovery channel resources based on time slotassignment shifting;

FIGS. 4A and 4B illustrate example scheduling matrices depictingassignments of neighbor discovery channel resources based on time slotand frequency assignment shifting;

FIGS. 5A and 5B illustrate example scheduling matrices depictingassignments of neighbor discovery channel resources based on matrixtransposition;

FIGS. 6A-6D illustrate example scheduling matrices depicting assignmentsof neighbor discovery channel resources based on a binary splittingscheme;

FIG. 7 is a flow chart of an example method of wireless networkcontrolled initiation of D2D communication; and

FIG. 8 is a flow chart of an example method of power control of aneighbor discovery signal.

DESCRIPTION OF EMBODIMENTS

In particular embodiments, and, as described in further detail below, awireless communication network may be configured to direct wirelessdevices to perform neighbor discovery and may instruct one or more setsof wireless devices to perform device-to-device (D2D) communicationbased on the neighbor discovery. As detailed below, the wirelesscommunication network may direct wireless devices to transmit andreceive neighbor discovery signals and may direct one or more sets ofwireless devices to perform D2D communication based on the neighbordiscovery signals. Additionally, the wireless communication network maybe configured to adjust the power of the neighbor discovery signals suchthat the neighbor discovery signals may not substantially interfere withother wireless signals.

Facilitating D2D communication may allow for lower power communicationbetween the wireless devices themselves and/or the wireless devices andan access point of the wireless communication network. Lower powercommunication may allow for reuse of a limited frequency band bylocalizing the use of each frequency band between the wireless devicesparticipating in D2D communication.

Embodiments of the present disclosure will be explained with referenceto the accompanying drawings.

FIG. 1 illustrates an example wireless communication network 100(referred to hereinafter as “network 100”) configured to control theinitiation of D2D communication between wireless devices, arranged inaccordance with the present disclosure. The network 100 may beconfigured to provide wireless communication services to one or morewireless devices 104 via one or more access points 102. The wirelesscommunication services may be voice services, data services, messagingservices, and/or any suitable combination thereof. The network 100 mayinclude a Frequency Division Multiple Access (FDMA) network, anOrthogonal FDMA (OFDMA) network, a Code Division Multiple Access (CDMA)network, a Time Division Multiple Access (TDMA) network, and/or anyother suitable wireless communication network. In some embodiments, thenetwork 100 may be configured as a third generation (3G) wirelesscommunication network and/or a fourth generation (4G) wirelesscommunication network. In these or other embodiments, the network 100may be configured as a long term evolution (LTE) wireless communicationnetwork.

The access point 102 may be any suitable wireless communication networkcommunication point and may include, by way of example but notlimitation, a base station, an evolved node “B” (eNB) base station, aremote radio head (RRH), or any other suitable communication point. Thewireless devices 104 may include any device that may use the network 100for obtaining wireless communication services and may include, by way ofexample and not limitation, a cellular phone, a smartphone, a personaldata assistant (PDA), a laptop computer, a personal computer, a tabletcomputer, or any other similar device.

In some embodiments, as mentioned above, the network 100 may beconfigured to supervise D2D communication between wireless devices 104.In some of these embodiments, the access point 102 may be configured todirect the discovery of neighboring wireless devices 104 such thatneighboring wireless devices 104 may be coupled together as a D2D pairperforming D2D communication. The terms “neighbor” and “neighboring”wireless devices may refer to wireless devices that may be in the samegeneral vicinity with respect to each other. The terms are not limitedto wireless devices being directly adjacent to each other, or thewireless device or wireless devices closest to a particular wirelessdevice.

For example, a wireless device 104 a may be configured to perform anetwork entry procedure with the access point 102 in response to thewireless device 104 a entering a geographical area serviced by theaccess point 102 (also referred to as a “cell”). Additionally, during orafter the network entry procedure, the wireless device 104 a may beconfigured to signal whether the wireless device 104 a is capable and/orwilling to participate in D2D communication with another wireless device104. A wireless device 104 b may be configured to perform similaroperations.

The access point 102 may be configured to instruct the wireless devices104 a and 104 b to participate in neighbor discovery when the wirelessdevices 104 a and 104 b indicate that they are capable and willing toparticipate in D2D communication. For example, the access point 102 maybe configured to perform radio resource control (RRC) signaling in whichthe access point 102 may instruct the wireless device 104 a and/or thewireless device 104 b to transmit a neighbor discovery signal.Additionally, the access point 102 may instruct the wireless device 104a and/or the wireless device 104 b to listen for a neighbor discoverysignal.

In the illustrated example, the access point 102 may instruct thewireless device 104 a to transmit a neighbor discovery signal and mayinstruct the wireless device 104 b to listen for the neighbor discoverysignal, at a particular time and frequency. Therefore, the wirelessdevice 104 a may be referred to as a “transmitting wireless device 104a” and the wireless device 104 b may be referred to as a “receivingwireless device 104 b” in the illustrated example. If the receivingwireless device 104 b receives the neighbor discovery signal transmittedby the transmitting wireless device 104 a, the receiving wireless devicemay be referred to as a discovered neighbor of the transmitting wirelessdevice 104 a.

In the illustrated embodiment, the access point 102 may be configured toperform scheduling of the transmission of the neighbor discovery signal.In some embodiments, the access point 102 may be configured to performthe scheduling by indicating to the transmitting wireless device 104 aparameters associated with transmitting the neighbor discovery signal.Additionally, the access point 102 may be configured to instruct thereceiving wireless device 104 b to listen for the neighbor discoverysignal based on the parameters.

The parameters may include a neighbor discovery signal channel (referredto hereinafter as a “discovery channel”) that may be used to transmitthe neighbor discovery signal; discovery channel resources (e.g., timeslots, frequencies, etc.) that may be used to transmit the neighbordiscovery signal; transmission sequences of the neighbor discoverysignal; transmission power of the neighbor discovery signal; and/orwhether or not transmission of the neighbor discovery signal is to berepeated. In some embodiments, the discovery channel may be a channelsuch as a sounding reference signal (SRS) channel, or may be a physicalneighbor discovery channel (PNDCH) that may be configured according tothe present disclosure as disclosed in further detail below.Additionally, in some embodiments, the access point 102 may determinethe transmission power of the neighbor discovery signal in a manner asdescribed below.

The parameters may also include instructions for the transmittingwireless device 104 a and the receiving wireless device 104 b totransmit and listen for, respectively, the neighbor discovery signalbased on an identifier associated with the access point 102, or based ona temporary identifier assigned by the access point 102. In someembodiments, the identifier may be a radio network temporary identifier(RNTI) associated with the access point 102. The identifier may be usedby the transmitting wireless device 104 a to transmit the neighbordiscovery signal according to a signal pattern associated with theidentifier. Additionally, the receiving wireless device 104 b may usethe identifier to recognize the neighbor discovery signal based on itssignal pattern.

The transmitting wireless device 104 a may be configured to transmit theneighbor discovery signal based on the received parameters in responseto receiving the instructions to transmit the neighbor discovery signalfrom the access point 102. Additionally, the receiving wireless device104 b may be configured to listen for the neighbor discovery signalaccording to the parameters received from the access point 102. Forexample, the transmitting wireless device 104 a may transmit theneighbor discovery signal over the PNDCH at a certain time slot,frequency, and signal power using the RNTI associated with the accesspoint 102 as indicated by the parameters received by the transmittingwireless device 104 a from the access point 102. The receiving wirelessdevice 104 b may be configured to listen for the neighbor discoverysignal by listening for signals transmitted over the PNDCH in theparticular transmission sequence, as indicated by the parametersreceived by the receiving wireless device 104 b from the access point102.

The receiving wireless device 104 b may also be configured to determineneighbor discovery signal information associated with the neighbordiscovery signal as received by the receiving wireless device 104 b. Forexample, the receiving wireless device 104 b may be configured todetermine discovery channel resources (e.g., frequency and time slot)associated with the neighbor discovery signal, a received signalstrength, a signal-to-noise ratio (SNR), etc., of the neighbor discoverysignal as received by the receiving wireless device 104 b.

The receiving wireless device 104 b may be configured to communicate theneighbor discovery signal information to the access point 102. Forexample, the receiving wireless device 104 b may be configured tocommunicate to the access point 102 an indication of discovery channelresources (e.g., frequency and time slot) associated with the neighbordiscovery signal as received by the receiving wireless device 104 b aswell as a received signal strength indicator (RSSI) of the neighbordiscovery signal as measured by the receiving wireless device 104 b.

The access point 102 may be configured to determine proximityinformation of the transmitting wireless device 104 a and the receivingwireless device 104 b based on the neighbor discovery signal informationthat may be received by the access point 102 from the receiving wirelessdevice 104 b. The proximity information may indicate a distance betweenthe transmitting wireless device 104 a and the receiving wireless device104 b. The proximity information may also indicate a path loss betweenthe transmitting wireless device 104 a and the receiving wireless device104 b.

Additionally, in some embodiments, the access point 102 may beconfigured to determine that the transmitting wireless device 104 atransmitted the neighbor discovery signal associated with the neighbordiscovery signal information received from the receiving wireless device104 b based on the discovery channel resource information included inthe neighbor discovery signal information.

For example, as mentioned above, the neighbor discovery signalinformation may include discovery channel resource information such as aslot time and a frequency associated with the neighbor discovery signal.The access point 102 may be configured to determine that thetransmitting wireless device 104 a is associated with the time slot andthe frequency included in the neighbor discovery signal information.Therefore, the access point 102 may determine that the transmittingwireless device 104 a was the wireless device that transmitted theneighbor discovery signal received by the receiving wireless device 104b. Accordingly, the access point 102 may be configured to determine thatthe receiving wireless device 104 b received the neighbor discoverysignal from the transmitting wireless device 104 a without the receivingwireless device 104 b knowing that the transmitting wireless device 102a transmitted the neighbor discovery signal. This configuration mayallow for a determination of proximity information of the transmittingwireless device 104 a and the receiving wireless device 104 b by theaccess point 102 without having location and global identificationinformation of the transmitting wireless device 104 a available to thereceiving wireless device 104 b and/or other wireless devices 104 of thenetwork 100.

The access point 102 may be configured to report the proximityinformation of the transmitting wireless device 104 a and the receivingwireless device 104 b to a network control unit 101 of the network 100.In some embodiments, the network control unit 101 may be included withand at the access point 102 and in other embodiments, the networkcontrol unit 101 may be remote from the access point 102. The networkcontrol unit 101 may be associated with a core network architecture of acore network of the network 100 and may be configured to performoperations associated with a core network protocol. For example, thenetwork control unit 101 may be included with a Mobility ManagementEntity (MME), a Serving Gateway (SGW), or a Packet Gateway (PGW) of anLTE core network.

Based on the proximity information, the network control unit 101 may beconfigured to determine whether the transmitting wireless device 104 aand the receiving wireless device 104 b are within sufficient range toparticipate in D2D communication with each other. If the network controlunit 101 determines that the transmitting wireless device 104 a and thereceiving wireless device 104 b are within sufficient range toparticipate in D2D communication, the network control unit 101 mayinstruct the access point 102 to initiate D2D communication between thetransmitting wireless device 104 a and the receiving wireless device 104b. The access point 102 may in turn instruct the transmitting wirelessdevice 104 a and the receiving wireless device 104 b to initiate and toparticipate in D2D communication.

Modifications, additions, or omissions may be made to FIG. 1 withoutdeparting from the scope of the present disclosure. For example, thenetwork 100 may include any number of access points 102 and wirelessdevices 104. Additionally, any number of D2D pairs may be discovered andinitiated with respect to the network 100. Further, the transmittingwireless device 104 a and/or the receiving wireless device 104 b may beincluded in other D2D pairs. Also, as mentioned above, the discoverychannel used to perform discovery may be a PNDCH. In some embodiments,the PNDCH may be configured such that the wireless devices 104configured to transmit neighbor discovery signals at approximately thesame time may also be configured to transmit neighbor discovery signalsat different times. The PNDCH may be configured to change which of thewireless devices 104 transmit neighbor discovery signals atapproximately the same time because the wireless devices 104transmitting neighbor discovery signals may not be able to receiveneighbor discovery signals from other of the wireless devices 104 alsotransmitting neighbor discovery signals at substantially the same time.

Further, at times, the access point 102 may instruct both the wirelessdevices 104 a and 104 b to listen for the neighbor discovery signal orto transmit the neighbor discovery signal at approximately the sametime. Additionally, at other times, the access point 102 may instructthe wireless device 104 b to transmit the neighbor discovery signalwhile instructing the wireless device 104 a to listen for the neighbordiscovery signal during the time that the wireless device 104 b istransmitting the neighbor discovery signal. Therefore, the“transmitting” wireless device 104 a and the “receiving” wireless device104 b may change their roles at various times.

FIG. 2 illustrates an example scheduling matrix 200 depicting aconfiguration of PNDCH resources, arranged in accordance with thepresent disclosure. The matrix 200 may be used to schedule PNDCHresources for a group of wireless devices, such as a group of thewireless devices 104 of FIG. 1. The matrix 200 may include columns 202a-202 d and rows 204 a-204 d. The columns 202 a-202 d may representdifferent time slots in which wireless devices of the group associatedwith the matrix 200 may be assigned to transmit a neighbor discoverysignal. Accordingly, the number of columns 202 a-202 d may indicate thenumber of time slots that may be used by the group of wireless devicesassociated with the matrix 200 to transmit neighbor discovery signals ina neighbor discovery round.

The rows 204 a-204 d may represent different frequencies over which thewireless devices of the group of wireless devices may be assigned tocommunicate the neighbor discovery signal. In some embodiments, thedifferent frequencies may be distinct frequencies that may be contiguousfrequencies within a particular frequency range. In these or otherembodiments, one or more of the frequencies may not be contiguous andmay be disjointed and distributed within a wide frequency range orbandwidth. Therefore, the number of rows 204 a-204 d may indicate thenumber of frequencies and, thus, the number of wireless devices, thatmay transmit a neighbor discovery signal within each time slot.

Each wireless device of the group of wireless devices associated withthe matrix 200 may be assigned to one of elements 206 a-206 p of thematrix 200. Each element 206 may indicate the frequency and time slotthat the wireless device assigned to it may use to transmit itscorresponding neighbor discovery signal. Each element 206 of the matrix200 may thus represent a PNDCH resource that may include a time slot andfrequency that may be assigned to a wireless device of the group ofwireless devices associated with the matrix 200 for transmission of anassociated neighbor discovery signal. For example, the element 206 a ofthe matrix 200 may indicate a PNDCH resource associated withtransmitting a neighbor discovery signal at a first time slot (“Slot 1”)associated with the column 202 a over a first frequency (“Freq. 1”)associated with the row 204 a. Therefore, a wireless device assigned tothe element 206 a may be assigned to transmit a neighbor discoverysignal over the first frequency and during the first time slot. In otherembodiments, the time slots may be represented by the rows 204 a-204 dof the matrix 200 and the frequencies may be represented by the columns202 a-202 d of the matrix 200.

As mentioned above, in some embodiments, wireless devices that arescheduled to transmit a neighbor discovery signal in a given time slotmay not be able to receive a neighbor discovery signal transmitted byanother wireless device during the same time slot. Therefore, in someembodiments, one or more of the wireless devices may be assigned to onetime slot shared by a set of wireless devices during one round ofneighbor discovery (which may be referred to as a “neighbor discoveryround”) and then may be assigned to another time slot shared by anotherset of wireless devices during another round of neighbor discovery. Theinclusion of multiple neighbor discovery rounds and the associatedshuffling of time slots assigned to the wireless devices between theneighbor discovery rounds may allow for the wireless devices in thegroup associated with the matrix 200 to discover each other, even if thewireless devices are given the same time slot during one of the neighbordiscovery rounds.

Further, in some instances, the frequencies assigned to one or morewireless devices may also be changed from one neighbor discovery roundto another. Sometimes the quality of a neighbor discovery signalreceived by a receiving wireless device from a transmitting wirelessdevice may be based on which frequency the neighbor discovery signal isbeing transmitted. Therefore, changing the frequency over which thetransmitting wireless device may transmit the neighbor discovery signalmay allow for improving the quality of the neighbor discovery signal asreceived by the receiving wireless device. FIGS. 4A and 4B, describedbelow, illustrate an example of shuffling time slot and frequencyassignments based on shifting time slot and frequency assignments.

FIGS. 3A and 3B illustrate example scheduling matrices 300 a and 300 b,respectively, depicting assignments of PNDCH resources to a group ofwireless devices (depicted as wireless devices WD 1-WD 16 in FIGS. 3Aand 3B) based on time slot assignment shifting, arranged in accordancewith the present disclosure. In the illustrated embodiments, and similarto the scheduling matrix 200 of FIG. 2, the scheduling matrices 300 aand 300 b may include columns 302 a-302 d and rows 304 a-304 d. Thecolumns 302 a-302 d may represent different time slots in which thewireless devices WD 1-WD 16 may be assigned to transmit a neighbordiscovery signal. The rows 304 a-304 d may represent differentfrequencies over which the wireless devices WD 1-WD 16 may be assignedto communicate the neighbor discovery signal.

In the illustrated embodiment, the scheduling matrix 300 a may indicatefrequency and time slot assignments over and in which the wirelessdevices WD 1-WD 16 may transmit neighbor discovery signals during afirst neighbor discovery round (depicted as “Round 1” in FIG. 3A).Accordingly, each of the wireless devices WD 1-WD 16 may be assigned toone of elements 306 a-306 p of the scheduling matrix 300 a, such thateach of the wireless devices WD 1-WD 16 may be assigned a particularPNDCH resource (e.g., time slot and transmission frequency) fortransmitting a neighbor discovery signal during the first neighbordiscovery round.

In some embodiments, a second neighbor discovery round (depicted as“Round 2” in FIG. 3B) may also be used for transmitting the neighbordiscovery signals. One or more of the wireless devices WD 1-WD 16 may beassigned a different time slot in the first and second neighbordiscovery rounds such that each of the wireless devices WD 1-WD 16 thatshare the same time slot in the first neighbor discovery round may notshare the same time slot in the second neighbor discovery round. In theillustrated embodiment of FIG. 3B, the scheduling matrix 300 b mayrepresent PNDCH resource assignments of the wireless devices WD 1-WD 16associated with the second neighbor discovery round.

In FIGS. 3A and 3B, the changing of time slot assignments from the firstneighbor discovery round to the second neighbor discovery round may beaccomplished through a cyclic shift of time slot assignments of thewireless devices WD 1-WD 16. In the illustrated embodiments of thescheduling matrices 300 a and 300 b, to produce the cyclic shift of timeslot assignments, the wireless devices assigned a first frequency,“Freq. 1,” may remain in their respective time slots from the schedulingmatrix 300 a to the scheduling matrix 300 b; the wireless devicesassigned a second frequency, “Freq. 2,” may shift one time slot over inthe scheduling matrix 300 b with respect to their assigned time slots inthe scheduling matrix 300 a; the wireless devices assigned a thirdfrequency, “Freq. 3,” may shift two time slots over in the samedirection in the scheduling matrix 300 b with respect to their assignedtime slots in the scheduling matrix 300 a; and the wireless devicesassigned a fourth frequency, “Freq. 4,” may shift three time slots overin the same direction in the scheduling matrix 300 b with respect totheir assigned time slots in the scheduling matrix 300 a.

For example, in the first neighbor discovery round, as illustrated bythe scheduling matrix 300 a, the wireless devices WD 1, WD 2, WD 3, andWD 4 may be assigned to the first frequency “Freq. 1” and may beassigned to time slots “Slot 1,” “Slot 2,” “Slot 3,” and “Slot 4,”respectively; the wireless devices WD 5, WD 6, WD 7, and WD 8 may beassigned to the second frequency “Freq. 2” and may be assigned to thetime slots “Slot 1,” “Slot 2,” “Slot 3,” and “Slot 4,” respectively; thewireless devices WD 9, WD 10, WD 11, and WD 12 may be assigned to thethird frequency “Freq. 3” and may be assigned to the time slots “Slot1,” “Slot 2,” “Slot 3,” and “Slot 4,” respectively; and the wirelessdevices WD 13, WD 14, WD 15, and WD 16 may be assigned to the fourthfrequency “Freq. 4” and may be assigned to the time slots “Slot 1,”“Slot 2,” “Slot 3,” and “Slot 4,” respectively. Therefore, in schedulingmatrix 300 a (and consequently the first neighbor discovery round), thewireless devices WD 1, WD 5, WD 9, and WD 13 may share a first timeslot, “Slot 1;” the wireless devices WD 2, WD 6, WD 10, and WD 14 mayshare a second time slot, “Slot 2;” the wireless devices WD 3, WD 7, WD11, and WD 15 may share a third time slot, “Slot 3;” and the wirelessdevices WD 4, WD 8, WD 12, and WD 16 may share a fourth time slot, “Slot4.”

In the second neighbor discovery round, as illustrated by the schedulingmatrix 300 b, the wireless devices WD 1, WD 2, WD 3, and WD 4 may stillbe assigned to the first frequency “Freq. 1;” the wireless devices WD 5,WD 6, WD 7, and WD 8 may still be assigned to the second frequency“Freq. 2;” the wireless devices WD 9, WD 10, WD 11, and WD 12 may stillbe assigned to the third frequency “Freq. 3;” and the wireless devicesWD 13, WD 14, WD 15, and WD 16 may still be assigned to the fourthfrequency “Freq. 4.” Additionally, the wireless devices WD 1, WD 2, WD3, and WD 4 may still be assigned to time slots “Slot 1,” “Slot 2,”“Slot 3,” and “Slot 4,” respectively.

However, the wireless devices WD 5, WD 6, WD 7, and WD 8 may be shiftedone time slot in the scheduling matrix 300 b with respect to thescheduling matrix 300 a such that the wireless devices WD 5, WD 6, WD 7,and WD 8 may be assigned to the time slots “Slot 4,” “Slot 1,” “Slot 2,”and “Slot 3,” respectively, in the scheduling matrix 300 b. Further, thewireless devices WD 9, WD 10, WD 11, and WD 12 may be shifted two timeslots in the scheduling matrix 300 b with respect to the schedulingmatrix 300 a such that the wireless devices WD 9, WD 10, WD 11, and WD12 may be assigned to the time slots “Slot 3,” “Slot 4,” “Slot 1,” and“Slot 2,” respectively, in the scheduling matrix 300 b. Additionally,the wireless devices WD 13, WD 14, WD 15, and WD 16 may be shifted threetime slots in the scheduling matrix 300 b with respect to the schedulingmatrix 300 a such that the wireless devices WD 13, WD 14, WD 15, and WD16 may be assigned to the time slots “Slot 2,” “Slot 3,” “Slot 4,” and“Slot 1,” respectively, in the scheduling matrix 300 b.

Therefore, in the scheduling matrix 300 b, the wireless devices WD 1, WD6, WD 11, and WD 16 may share the first time slot, “Slot 1;” thewireless devices WD 2, WD 7, WD 12, and WD 13 may share the second timeslot, “Slot 2;” the wireless devices WD 3, WD 8, WD 9, and WD 14 mayshare the third time slot, “Slot 3;” and the wireless devices WD 4, WD5, WD 10, and WD 15 may share the fourth time slot, “Slot 4.” Asmentioned above, in the scheduling matrix 300 a, the wireless devices WD1, WD 5, WD 9, and WD 13 may share the first time slot, “Slot 1;” thewireless devices WD 2, WD 6, WD 10, and WD 14 may share the second timeslot, “Slot 2;” the wireless devices WD 3, WD 7, WD 11, and WD 15 mayshare the third time slot, “Slot 3;” and the wireless devices WD 4, WD8, WD 12, and WD 16 may share the fourth time slot, “Slot 4.”Accordingly, the same wireless devices may not share the same time slotsin the scheduling matrices 300 a and 300 b such that the same wirelessdevices may not transmit the neighbor discovery signal at the same timein the first and second neighbor discovery rounds associated with thescheduling matrices 300 a and 300 b, respectively.

Modifications may be made to the scheduling matrices 300 a and 300 bwithout departing from the scope of the present disclosure. For example,the number of columns 302 (and accordingly a number of time slots)and/or the number of rows 304 (and accordingly a number of frequencies)may vary. Further, the manner of performing the cyclic time shift maydiffer from that described. For example, the number of time slots anddirection by which a wireless device may be shifted time slotassignments may vary. Additionally, in some embodiments, the time slotsmay be represented by the rows 304 a-304 d of the scheduling matrices300 a and 300 b and the frequencies may be represented by the columns302 a-302 d of the scheduling matrices 300 a and 300 b.

FIGS. 4A and 4B illustrate example scheduling matrices 400 a and 400 b,respectively, depicting assignments of PNDCH resources to wirelessdevices WD 1-WD 16 based on time slot and frequency assignment shifting,arranged in accordance with the present disclosure. In the illustratedembodiments and similar to the scheduling matrix 200 of FIG. 2, thescheduling matrices 400 a and 400 b may include columns 402 a-402 d androws 404. The columns 402 a-402 d may represent different time slots inwhich the wireless devices WD 1-WD 16 may be assigned to transmit aneighbor discovery signal. The rows 404 a-404 d may represent differentfrequencies over which the wireless devices WD 1-WD 16 may be assignedto communicate their respective neighbor discovery signals.

In the illustrated embodiment and similar to the scheduling matrix 300 aof FIG. 3A, the scheduling matrix 400 a may indicate frequency and timeslot assignments over and in which the wireless devices WD 1-WD 16 maytransmit neighbor discovery signals during a first neighbor discoveryround (illustrated as “Round 1” in FIG. 4A) by assigning each of thewireless devices WD 1-WD 16 to one of elements 406 a-406 p of thescheduling matrix 400 a. Additionally, similar to the scheduling matrix300 b of FIG. 3B, the scheduling matrix 400 b may indicate frequency andtime slot assignments over and in which the wireless devices WD 1-WD 16may transmit neighbor discovery signals during a second neighbordiscovery round (illustrated as “Round 2” in FIG. 4B) by assigning eachof the wireless devices WD 1-WD 16 to one of elements 406 a-406 p of thescheduling matrix 400 b.

In FIGS. 4A and 4B, the changing of time slot assignments from the firstneighbor discovery round to the second neighbor discovery round may beaccomplished through a cyclic shift of time slot assignments of thewireless devices WD 1-WD 16 similar to the cyclic shift of time slotassignments described with respect to FIGS. 3A and 3B. However, unlikein FIGS. 3A and 3B, one or more of the wireless devices WD 1-WD 16 mayalso be assigned different frequencies in the scheduling matrix 400 bwith respect to their assigned frequencies in the scheduling matrix 400a. As mentioned above, the changing of frequency assignments may allowfor improved neighbor discovery signal communication as some frequenciesmay experience less pathloss than other frequencies from one of thewireless devices WD 1-WD 16 to another.

In the illustrated embodiments of the scheduling matrices 400 a and 400b and similar to as described above with respect to the schedulingmatrices 300 a and 300 b of FIGS. 3A and 3B, respectively, to producethe cyclic shift in time slots, the wireless devices assigned a firstfrequency, “Freq. 1,” in the scheduling matrix 400 a may remain in theirrespective time slots from the scheduling matrix 400 a to the schedulingmatrix 400 b; the wireless devices assigned a second frequency, “Freq.2,” in the scheduling matrix 400 a may shift one time slot over in thescheduling matrix 400 b with respect to their assigned time slots in thescheduling matrix 400 a; the wireless devices assigned a thirdfrequency, “Freq. 3,” in the scheduling matrix 400 a may shift two timeslots over in the scheduling matrix 400 b with respect to their assignedtime slots in the scheduling matrix 400 a; and the wireless devicesassigned a fourth frequency, “Freq. 4,” in the scheduling matrix 400 amay shift three time slots over in the scheduling matrix 400 b withrespect to their assigned time slots in the scheduling matrix 400 a.

However, unlike the scheduling matrices 300 a and 300 b, in thescheduling matrices 400 a and 400 b, the wireless devices assigned to afirst time slot, “Slot 1,” in the scheduling matrix 400 b may beassigned to a different frequency in the scheduling matrix 400 b withrespect to their frequency assignment in the scheduling matrix 400 abased on a frequency shift of one. The wireless devices assigned to asecond time slot, “Slot 2,” in the scheduling matrix 400 b may beassigned to a different frequency in the scheduling matrix 400 b withrespect to their frequency assignment in the scheduling matrix 400 abased on a frequency shift of two. The wireless devices assigned to athird time slot, “Slot 3,” in the scheduling matrix 400 b may beassigned to a different frequency in the scheduling matrix 400 b withrespect to their frequency assignment in the scheduling matrix 400 abased on a frequency shift of three; and the wireless devices assignedto a fourth time slot, “Slot 4,” in the scheduling matrix 400 b may beassigned to their same frequencies in the scheduling matrix 400 b withrespect to their frequency assignment in the scheduling matrix 400 a.The frequency shifting may thus produce a change in frequencyassignments between the first and second neighbor discovery roundsassociated with the scheduling matrices 400 a and 400 b, respectively.

For example, in the first neighbor discovery round, as illustrated bythe scheduling matrix 400 a and similar to the scheduling matrix 300 aof FIG. 3A, the wireless devices WD 1, WD 2, WD 3, and WD 4 may beassigned to the first frequency “Freq. 1” and may be assigned to thetime slots “Slot 1,” “Slot 2,” “Slot 3,” and “Slot 4,” respectively; thewireless devices WD 5, WD 6, WD 7, and WD 8 may be assigned to thesecond frequency “Freq. 2” and may be assigned to the time slots “Slot1,” “Slot 2,” “Slot 3,” and “Slot 4,” respectively; the wireless devicesWD 9, WD 10, WD 11, and WD 12 may be assigned to the third frequency“Freq. 3” and may be assigned to the time slots “Slot 1,” “Slot 2,”“Slot 3,” and “Slot 4,” respectively; and the wireless devices WD 13, WD14, WD 15, and WD 16 may be assigned to the fourth frequency “Freq. 4”and may be assigned to the time slots “Slot 1,” “Slot 2,” “Slot 3,” and“Slot 4,” respectively. Therefore, in the scheduling matrix 400 a, thewireless devices WD 1, WD 5, WD 9, and WD 13 may share a first timeslot, “Slot 1,” wireless devices WD 2, WD 6, WD 10, and WD 14 may sharea second time slot, “Slot 2,” wireless devices WD 3, WD 7, WD 11, and WD15 may share a third time slot, “Slot 3,” and wireless devices WD 4, WD8, WD 12, and WD 16 may share a fourth time slot, “Slot 4.”

In the second neighbor discovery round, as illustrated by the schedulingmatrix 400 b and similar to the scheduling matrix 300 b of FIG. 3B, thewireless devices WD 1, WD 2, WD 3, and WD 4 may still be assigned to thetime slots “Slot 1,” “Slot 2,” “Slot 3,” and “Slot 4,” respectively, inthe scheduling matrix 400 b. Additionally, the wireless devices WD 5, WD6, WD 7, and WD 8 may be shifted one time slot in the scheduling matrix400 b with respect to the scheduling matrix 400 a such that the wirelessdevices WD 5, WD 6, WD 7, and WD 8 may be assigned to the time slots“Slot 4,” “Slot 1,” “Slot 2,” and “Slot 3,” respectively, in thescheduling matrix 400 b. Further, the wireless devices WD 9, WD 10, WD11, and WD 12 may be shifted two time slots in the scheduling matrix 400b with respect to the scheduling matrix 400 a such that the wirelessdevices WD 9, WD 10, WD 11, and WD 12 may be assigned to time slots“Slot 3,” “Slot 4,” “Slot 1,” and “Slot 2,” respectively, in thescheduling matrix 400 b. Additionally, the wireless devices WD 13, WD14, WD 15, and WD 16 may be shifted three time slots in the schedulingmatrix 300 b with respect to the scheduling matrix 400 a such that thewireless devices WD 13, WD 14, WD 15, and WD 16 may be assigned to timeslots “Slot 2,” “Slot 3,” “Slot 4,” and “Slot 1,” respectively, in thescheduling matrix 400 b.

Additionally, in scheduling matrix 400 b, the wireless devices WD 1, WD6, WD 11 and WD 16 of the time slot “Slot 1” of the scheduling matrix400 b may be shifted by one frequency with respect to their assignedfrequencies in the scheduling matrix 400 a such that the wirelessdevices WD 1, WD 6, WD 11 and WD 16 may be assigned to frequencies“Freq. 2,” “Freq. 3,” “Freq. 4,” and “Freq. 1,” respectively, in thescheduling matrix 400 b. Further, the wireless devices WD 2, WD 7, WD 12and WD 13 of the time slot “Slot 2” of the scheduling matrix 400 b maybe shifted by two frequencies with respect to their assigned frequenciesin the scheduling matrix 400 a such that the wireless devices WD 2, WD7, WD 12 and WD 13 may be assigned to frequencies “Freq. 3,” “Freq. 4,”“Freq. 1,” and “Freq. 2,” respectively, in the scheduling matrix 400 b.Also, the wireless devices WD 3, WD 8, WD 9 and WD 14 of the time slot“Slot 3” of the scheduling matrix 400 b may be shifted by threefrequencies with respect to their assigned frequencies in the schedulingmatrix 400 a such that the wireless devices WD 3, WD 8, WD 9 and WD 14may be assigned to frequencies “Freq. 4,” “Freq. 1,” “Freq. 2,” and“Freq. 3,” respectively, in the scheduling matrix 400 b. Additionally,the wireless devices WD 4, WD 5, WD 10, and WD 15 of the time slot “Slot4” of the scheduling matrix 400 b may be assigned to the samefrequencies in the scheduling matrix 400 b as in the scheduling matrix400 a.

Therefore, in the scheduling matrices 400 a and 400 b, the same wirelessdevices may not share the same time slots or neighbor discovery signalfrequencies in the first and second neighbor discovery rounds.Accordingly, the same wireless devices may not transmit the neighbordiscovery signal at the same time or over the same frequencies in thefirst and second neighbor discovery rounds associated with thescheduling matrices 400 a and 400 b, respectively.

Modifications may be made to the scheduling matrices 400 a and 400 bwithout departing from the scope of the present disclosure. For example,the number of columns 402 (and accordingly the number of time slots)and/or the number of rows 404 (and accordingly the number offrequencies) may vary. Further, the manner of performing the cyclic timeshift and/or frequency shift may differ from that described. Forexample, the number of time slots or frequencies and directions by whicha wireless device may be shifted may vary. Additionally, in someembodiments, the time slots may be represented by the rows 404 a-404 dof the scheduling matrices 400 a and 400 b and the frequencies may berepresented by the columns 402 a-402 d of the scheduling matrices 400 aand 400 b.

FIGS. 5A and 5B illustrate example scheduling matrices 500 a and 500 b,respectively, depicting assignments of PNDCH resources to the wirelessdevices WD 1-WD 16 based on matrix transposition, arranged in accordancewith the present disclosure. In the illustrated embodiments, and similarto the scheduling matrix 200 of FIG. 2, the scheduling matrices 500 aand 500 b may include columns 502 a-502 d and rows 504 a-504 d. Thecolumns 502 a-502 d may represent different time slots in which thewireless devices WD 1-WD 16 may be assigned to transmit a neighbordiscovery signal. The rows 504 a-504 d may represent differentfrequencies over which the wireless devices WD 1-WD 16 may be assignedto communicate their neighbor discovery signals.

In the illustrated embodiment and similar to the scheduling matrix 300 aof FIG. 3A, the scheduling matrix 500 a may indicate frequency and timeslot assignments over and in which the wireless devices WD 1-WD 16 maytransmit neighbor discovery signals during a first neighbor discoveryround (illustrated as “Round 1” in FIG. 5A) by assigning each of thewireless devices WD 1-WD 16 to one of elements 506 a-506 p of thescheduling matrix 500 a. Additionally, similar to the scheduling matrix300 b of FIG. 3B, the scheduling matrix 500 b may indicate frequency andtime slot assignments over and in which the wireless devices WD 1-WD 16may transmit neighbor discovery signals during a second neighbordiscovery round (illustrated as “Round 2” in FIG. 5B) by assigning eachof the wireless devices WD 1-WD 16 to one of elements 506 a-506 p of thescheduling matrix 500 b.

In FIGS. 5A and 5B, the changing of time slot and frequency assignmentsfrom the first neighbor discovery round to the second neighbor discoveryround may be accomplished through a transposition of the schedulingmatrix 500 a to generate the scheduling matrix 500 b. During matrixtransposition, the rows of a matrix are assigned as the columns of anassociated transposed matrix and the columns of the matrix are assignedas the rows of the associated transposed matrix. Accordingly, in theillustrated embodiments of the scheduling matrices 500 a and 500 b, thewireless devices assigned to a first time slot (“Slot 1”) in thescheduling matrix 500 a may be assigned to a first frequency (“Freq. 1”)in the scheduling matrix 500 b; the wireless devices assigned to asecond time slot (“Slot 2”) in the scheduling matrix 500 a may beassigned to a second frequency (“Freq. 2”) in the scheduling matrix 500b; the wireless devices assigned to a third time slot (“Slot 3”) in thescheduling matrix 500 a may be assigned to a third frequency (“Freq. 3”)in the scheduling matrix 500 b; and the wireless devices assigned to afourth time slot (“Slot 4”) in the scheduling matrix 500 a may beassigned to a fourth frequency (“Freq. 4”) in the scheduling matrix 500b.

For example, in the scheduling matrix 500 a and similar to thescheduling matrix 300 a of FIG. 3A, the wireless devices WD 1, WD 2, WD3, and WD 4 may be assigned to the first frequency “Freq. 1” and may beassigned to the time slots “Slot 1,” “Slot 2,” “Slot 3,” and “Slot 4,”respectively; the wireless devices WD 5, WD 6, WD 7, and WD 8 may beassigned to the second frequency “Freq. 2” and may be assigned to thetime slots “Slot 1,” “Slot 2,” “Slot 3,” and “Slot 4,” respectively; thewireless devices WD 9, WD 10, WD 11, and WD 12 may be assigned to thethird frequency “Freq. 3” and may be assigned to the time slots “Slot1,” “Slot 2,” “Slot 3,” and “Slot 4,” respectively; and the wirelessdevices WD 13, WD 14, WD 15, and WD 16 may be assigned to the fourthfrequency “Freq. 4” and may be assigned to the time slots “Slot 1,”“Slot 2,” “Slot 3,” and “Slot 4,” respectively.

The transposition of the scheduling matrix 500 a to generate thescheduling matrix 500 b may be such that the wireless devices WD 1, WD2, WD 3, and WD 4 may be assigned to the first time slot (“Slot 1”) andmay be assigned to the frequencies “Freq. 1,” “Freq. 2,” “Freq. 3,” and“Freq. 4,” respectively, in the scheduling matrix 500 b; the wirelessdevices WD 5, WD 6, WD 7, and WD 8 may be assigned to the second timeslot (“Slot 2”) and may be assigned to the frequencies “Freq. 1,” “Freq.2,” “Freq. 3,” and “Freq. 4,” respectively, in the scheduling matrix 500b; the wireless devices WD 9, WD 10, WD 11, and WD 12 may be assigned tothe third time slot (“Slot 3”) and may be assigned to the frequencies“Freq. 1,” “Freq. 2,” “Freq. 3,” and “Freq. 4,” respectively, in thescheduling matrix 500 b; and the wireless devices WD 13, WD 14, WD 15,and WD 16 may be assigned to the fourth time slot (“Slot 4”) and may beassigned to the frequencies “Freq. 1,” “Freq. 2,” “Freq. 3,” and “Freq.4,” respectively, in the scheduling matrix 500 b.

Therefore, in the scheduling matrices 500 a and 500 b, the same wirelessdevices may not share the same time slots or neighbor discovery signalfrequencies. Accordingly, as with the scheduling matrices 400 a and 400b, the same wireless devices may not transmit the neighbor discoverysignal at the same time or over the same frequencies in the first andsecond neighbor discovery rounds associated with the scheduling matrices500 a and 500 b, respectively.

Modifications may be made to the scheduling matrices 500 a and 500 bwithout departing from the scope of the present disclosure. For example,the number of columns 502 (and accordingly the number of time slots)and/or the number of rows 504 (and accordingly the number offrequencies) may vary. Additionally, in some embodiments, the time slotsmay be represented by the rows 504 a-504 d of the scheduling matrices500 a and 500 b and the frequencies may be represented by the columns502 a-502 d of the scheduling matrices 500 a and 500 b

FIGS. 6A-6D illustrate example scheduling matrices 600 a, 600 b, 600 c,and 600 d, respectively, depicting assignments of PNDCH resources towireless devices WD 1-WD 16 based on a binary splitting scheme, arrangedin accordance with the present disclosure. In the illustratedembodiments, and similar to the scheduling matrix 200 of FIG. 2, thescheduling matrices 600 a-600 d may include columns 602 a-602 d and rows604 a-604 d. The columns 602 a-602 d may represent different time slotsin which the wireless devices WD 1-WD 16 may be assigned to transmit aneighbor discovery signal. The rows 604 a-604 d may represent differentfrequencies over which the wireless devices WD 1-WD 16 may be assignedto communicate their neighbor discovery signals. In the illustratedembodiment, the scheduling matrices 600 a-600 d may indicate frequencyand time slot assignments over and in which the wireless devices WD 1-WD16 may transmit neighbor discovery signals during first, second, third,and fourth neighbor discovery rounds, respectively, by assigning each ofthe wireless devices WD 1-WD 16 to one of elements 606 a-606 p of thescheduling matrices 600 a-600 d.

In FIGS. 6A-6D, the changing of time slot and frequency assignmentsbetween neighbor discovery rounds may be accomplished through a binarysplitting scheme. The binary splitting scheme may be used to assigndifferent ones of the wireless devices WD 1-WD 16 to different timeslots in different neighbor discovery rounds such that the wirelessdevices WD 1-WD 16 may discover each other during at least one of theneighbor discovery rounds. Additionally, the binary splitting scheme mayassign different frequencies to different ones of the wireless devicesWD 1-WD 16 during different neighbor discovery rounds.

The binary splitting scheme may be performed with respect to schedulingmatrices that are associated with scheduling wireless devices of a groupaccording to two time slots, as illustrated by the scheduling matrices600 a-600 d. To generate the time slot and frequency assignments for thesecond neighbor discovery round, the binary splitting scheme may dividethe elements wireless devices assigned to the first time slot in thefirst neighbor discovery round into two equal number groups offirst-time-slot wireless devices. The binary splitting scheme may alsodivide the wireless devices assigned to the second time slot in thefirst neighbor discovery round into two equal number groups ofsecond-time-slot wireless devices. To generate the time slot andfrequency assignments for the second neighbor discovery round, one groupof first-time-slot wireless devices may exchange assignments with agroup of second-time-slot wireless devices.

To generate the time slot and frequency assignments for the thirdneighbor discovery round, the number of time slot groups used may bedoubled with respect to the number of time slot groups used to generatethe time slot and frequency assignments for the second neighbordiscovery round. Therefore, the wireless devices assigned to the firsttime slot in the second neighbor discovery round may be divided intofour equal number first-time-slot groups and the wireless devicesassigned to the second time slot in the second neighbor discovery roundmay be divided into four equal number second-time-slot groups. Togenerate the time slot and frequency assignments for the third neighbordiscovery round, two groups of the first-time-slot wireless devices mayexchange assignments with two groups of the second-time-slot wirelessdevices.

In some embodiments, this process of doubling the number offirst-time-slot groups and second-time-slot groups between neighbordiscovery rounds and exchanging assignments between half of the timeslot groups may be repeated until the time slot and frequencyassignments for a neighbor discovery round are based on exchangingassignments between time slot groups that may include only one wirelessdevice. After the time slot groups include only one wireless device, thebinary splitting scheme may repeat. Accordingly, the number of neighbordiscovery rounds used in the binary splitting scheme may be based on thenumber of wireless devices assigned to each time slot.

As mentioned earlier, FIGS. 6A-6D and their associated matrices 600a-600 d illustrate an example operation of the binary splitting scheme.In the illustrated example of FIGS. 6A-6D, the number of wirelessdevices assigned to each time slot may be eight such that the number ofneighbor discovery rounds that may occur before repeating assignmentsmay be four.

As mentioned above, the scheduling matrix 600 a of FIG. 6A may beassociated with the time slot and frequency assignments of the wirelessdevices WD 1-WD 16 in a first round of neighbor discovery (depicted as“Round 1”). As illustrated by the scheduling matrix 600 a, in the firstneighbor discovery round, the wireless devices WD 1-WD 8 may be assignedto a first time slot (“Slot 1”) and frequencies “Freq. 1”-“Freq. 8,”respectively. Additionally, in the first neighbor discovery round, thewireless devices WD 9-WD 16 may be assigned to a second time slot (“Slot2”) and frequencies “Freq. 1”-“Freq. 8,” respectively.

To determine the time slot and frequency assignments for the secondround of neighbor discovery (depicted as “Round 2” in FIG. 6B), thebinary splitting scheme may be used to generate the scheduling matrix600 b, based on the scheduling matrix 600 a. For example, the wirelessdevices WD 1-WD 8 in the first time slot (“Slot 1”) in the schedulingmatrix 600 a may be divided into a first-time-slot group “A1” and afirst-time-slot group “B1.” The first-time-slot group “A1” may includethe wireless devices WD1-WD 4 and the first-time-slot group “B1” mayinclude the wireless devices WD 5-WD 8. Additionally, the wirelessdevices WD 9-WD 16 in the second time slot (“Slot 2”) in the schedulingmatrix 600 a may be divided into a second-time-slot group “A1” and asecond-time-slot group “B1.” The second-time-slot group “A1” may includethe wireless devices WD9-WD 12 and the second-time-slot group “B1” mayinclude the wireless devices WD 13-WD 16. To generate the schedulingmatrix 600 b (and consequently the time slot and frequency assignmentsfor the second neighbor discovery round), the first-time-slot group “B1”(wireless devices WD 5-WD 8) of the scheduling matrix 600 a may switchtime slot and frequency assignments with the second-time-slot group “A1”(wireless devices WD 9-WD 12) of the scheduling matrix 600 a.Additionally, the time slot and frequency assignments of the wirelessdevices associated with the first-time-slot group “A1” (wireless devicesWD 1-WD 4) and the second-time-slot group “B1” (wireless devices WD13-WD 16) of the scheduling matrix 600 a may be the same in thescheduling matrix 600 b as in the scheduling matrix 600 a.

Therefore, as illustrated by the scheduling matrix 600 b, in the secondneighbor discovery round, the wireless devices WD 1-WD 4 and WD 9-WD 12may be assigned to the first time slot (“Slot 1”) and may be assigned tothe frequencies “Freq. 1”-“Freq. 8,” respectively. Additionally, in thesecond neighbor discovery round, the wireless devices WD 5-WD 8 and WD13-WD 16 may be assigned to the second time slot (“Slot 2”) and may beassigned to the frequencies “Freq. 1”-“Freq. 8,” respectively.

To determine the time slot and frequency assignments for the third roundof neighbor discovery (depicted as “Round 3” in FIG. 6C), the binarysplitting scheme may be used to generate the scheduling matrix 600 c,based on the scheduling matrix 600 b. For example, the wireless devicesWD 1-WD 4 and WD 9-WD 12 in the first time slot (“Slot 1”) in thescheduling matrix 600 b may be divided into a first-time-slot group“A2,” a first-time-slot group “B2,” a first-time-slot group “C2,” and afirst-time-slot group “D2.” The first-time-slot group “A2” of thescheduling matrix 600 b may include the wireless devices WD1 and WD 2;the first-time-slot group “B2” of the scheduling matrix 600 b mayinclude the wireless devices WD 3 and WD 4; the first-time-slot group“C2” of the scheduling matrix 600 b may include the wireless devices WD9 and WD 10; and the first-time-slot group “D2” of the scheduling matrix600 b may include the wireless devices WD 11 and WD 12.

Additionally, the wireless devices WD 5-WD 8 and WD 13-WD 16 in thesecond time slot (“Slot 2”) in the scheduling matrix 600 b may bedivided into a second-time-slot group “A2,” a second-time-slot group“B2,” a second-time-slot group “C2,” and a second-time-slot group “D2.”The second-time-slot group “A2” of the scheduling matrix 600 b mayinclude the wireless devices WD 5 and WD 6; the second-time-slot group“B2” of the scheduling matrix 600 b may include the wireless devices WD7 and WD 8; the second-time-slot group “C2” of the scheduling matrix 600b may include the wireless devices WD 13 and WD 14; and thesecond-time-slot group “D2” of the scheduling matrix 600 b may includethe wireless devices WD 15 and WD 16.

To generate the scheduling matrix 600 c (and consequently the time slotand frequency assignments for the third neighbor discovery round), thefirst-time-slot group “B2” (wireless devices WD 3 and WD 4) of thescheduling matrix 600 b may switch time slot and frequency assignmentswith the second-time-slot group “A2” (wireless devices WD 5 and WD 6) ofthe scheduling matrix 600 b. Further, the first-time-slot group “D2”(wireless devices WD 11 and WD 12) of the scheduling matrix 600 b mayswitch time slot and frequency assignments with the second-time-slotgroup “C2” (wireless devices WD 13 and WD 14) of the scheduling matrix600 b. Additionally, the time slot and frequency assignments of thewireless devices associated with the first-time-slot groups “A2”(wireless devices WD 1 and WD 2) and “C2” (wireless devices WD 9 and WD10) and the second-time-slot groups “B2” (wireless devices WD 7 and WD8) and “D2” (wireless devices WD 15 and WD 16) of the scheduling matrix600 b may be the same in the scheduling matrix 600 c as in thescheduling matrix 600 b.

Therefore, as illustrated by the scheduling matrix 600 c, in the thirdneighbor discovery round, the wireless devices WD 1, WD 2, WD 5, WD 6,WD 9, WD 10, WD 13, and WD 14 may be assigned to the first time slot(“Slot 1”) and may be assigned to the frequencies “Freq. 1”-“Freq. 8,”respectively. Additionally, in the third neighbor discovery round, thewireless devices WD 3, WD 4, WD 7, WD 8, WD 11, WD 12, WD 15, and WD 16may be assigned to the second time slot (“Slot 2”) and may be assignedto frequencies “Freq. 1”-“Freq. 8,” respectively.

To determine the time slot and frequency assignments for the fourthround of neighbor discovery (depicted as “Round 4” in FIG. 6D), thebinary splitting scheme may be used to generate the scheduling matrix600 d based on the scheduling matrix 600 c. For example, the wirelessdevices WD 1, WD 2, WD 5, WD 6, WD 9, WD 10, WD 13, and WD 14 in thefirst time slot (“Slot 1”) in the scheduling matrix 600 c may be dividedinto a first-time-slot group “A3,” a first-time-slot group “B3,” afirst-time-slot group “C3,” a first-time-slot group “D3,” afirst-time-slot group “E3,” a first-time-slot group “F3,” afirst-time-slot group “G3,” and a first-time-slot group “H3.” Thefirst-time-slot group “A3” of the scheduling matrix 600 c may includethe wireless device WD 1; the first-time-slot group “B3” of thescheduling matrix 600 c may include the wireless device WD 2; thefirst-time-slot group “C3” of the scheduling matrix 600 c may includethe wireless device WD 5, the first-time-slot group “D3” of thescheduling matrix 600 c may include the wireless device WD 6; thefirst-time-slot group “E3” of the scheduling matrix 600 c may includethe wireless device WD 9; the first-time-slot group “F3” of thescheduling matrix 600 c may include the wireless device WD 10; thefirst-time-slot group “G3” of the scheduling matrix 600 c may includethe wireless device WD 13; and the first-time-slot group “H3” of thescheduling matrix 600 c may include the wireless device WD 14.

Additionally, the wireless devices in the second time slot in thescheduling matrix 600 c may be divided into a second-time-slot group“A3,” a second-time-slot group “B3,” a second-time-slot group “C3,” asecond-time-slot group “D3,” a second-time-slot group “E3,” asecond-time-slot group “F3,” a second-time-slot group “G3,” and asecond-time-slot group “H3.” The second-time-slot group “A3” of thescheduling matrix 600 c may include the wireless device WD 3; thesecond-time-slot group “B3” of the scheduling matrix 600 c may includethe wireless device WD 4; the second-time-slot group “C3” of thescheduling matrix 600 c may include the wireless device WD 7, thesecond-time-slot group “D3” of the scheduling matrix 600 c may includethe wireless device WD 8; the second-time-slot group “E3” of thescheduling matrix 600 c may include the wireless device WD 11; thesecond-time-slot group “F3” of the scheduling matrix 600 c may includethe wireless device WD 12; the second-time-slot group “G3” of thescheduling matrix 600 c may include the wireless device WD 15; and thesecond-time-slot group “H3” of the scheduling matrix 600 c may includethe wireless device WD 16.

To generate the scheduling matrix 600 d (and consequently the time slotand frequency assignments for the fourth neighbor discovery round), thefirst-time-slot group “B3” (wireless device WD 2) of the schedulingmatrix 600 c may switch time slot and frequency assignments with thesecond-time-slot group “A3” (wireless device WD 3) of the schedulingmatrix 600 c. Further, the first-time-slot group “D3” (wireless deviceWD 6) of the scheduling matrix 600 c may switch time slot and frequencyassignments with the second-time-slot group “C3” (wireless device WD 7)of the scheduling matrix 600 c. Also, the first-time-slot group “F3”(wireless device WD 10) of the scheduling matrix 600 c may switch timeslot and frequency assignments with the second-time-slot group “E3”(wireless device WD 11) of the scheduling matrix 600 c. Further, thefirst-time-slot group “H3” (wireless device WD 14) of the schedulingmatrix 600 c may switch time slot and frequency assignments with thesecond-time-slot group “G3” (wireless device WD 15) of the schedulingmatrix 600 c. The time slot and frequency assignments of the wirelessdevices associated with the first-time-slot groups “A3” (wireless deviceWD 1), “C3” (wireless device WD 5), “E3” (wireless device WD 9), and“G3” (wireless device WD 13). Also, the time slot and frequencyassignments of the wireless devices associated with the second-time-slotgroups “B3” (wireless device WD 4), “D3” (wireless device WD 8), “F3”(wireless device WD 12), and “H3” (wireless device WD 16) of thescheduling matrix 600 c may be the same in the scheduling matrix 600 das in the scheduling matrix 600 c.

Therefore, as illustrated by the scheduling matrix 600 d, in the fourthneighbor discovery round, the wireless devices WD 1, WD 3, WD 5, WD 7,WD 9, WD 11, WD 13, and WD 15 may be assigned to the first time slot(“Slot 1”) and may be assigned to the frequencies “Freq. 1”-“Freq. 8,”respectively. Additionally, in the fourth neighbor discovery round, thewireless devices WD 2, WD 4, WD 6, WD 8, WD 10, WD 12, WD 14, and WD 16may be assigned to the second time slot (“Slot 2”) and may be assignedto frequencies “Freq. 1”-“Freq. 8,” respectively.

As mentioned above, because the time slot groups used to generate thescheduling matrix 600 d may each include one of the wireless devices WD1-WD 16, the subsequent neighbor discovery round after the fourthneighbor discovery round may be the first neighbor discovery round inwhich the time slot and frequency assignments may be based on thescheduling matrix 600 a.

Therefore, the binary splitting scheme may be used with respect to thescheduling matrices 600 a-600 d (and their associated neighbor discoveryrounds) such that the same wireless devices may not share the same timeslots or neighbor discovery signal frequencies in every neighbordiscovery round. Accordingly, the same wireless devices may not transmitthe neighbor discovery signal at the same time or over the samefrequencies in all the neighbor discovery rounds associated with thescheduling matrices 600 a-600 d.

Modifications may be made to the scheduling matrices 600 a-600 d withoutdeparting from the scope of the present disclosure. For example, thenumber of rows 604 (and accordingly number of frequencies per time slot)may vary. Additionally, in some embodiments, the rows 604 a-604 d mayindicate time slots and the columns 602 a-602 d may indicatefrequencies.

Additionally, in some instances the number of wireless devices to begiven time slot and frequency assignments based on the binary splittingscheme may not be a power of two. In some of these instances, one ormore of the elements 606 a-606 p may be populated with a dummy wirelessdevice that may not exist and the binary splitting scheme may proceed asdescribed above with the dummy wireless devices and the actual wirelessdevices. For example, if the number of wireless devices given time slotand frequency assignments based on the binary splitting scheme andscheduling matrices 606 a-606 d above is ten, six of the elements 606a-606 p may be populated with dummy wireless devices while performingthe binary splitting scheme.

Further, although the above description has been given with respect todividing the wireless devices WD 1-WD 16 associated with the schedulingmatrices 602 a-602 d into various time slot groups, the same process maybe performed with respect to dividing the elements 606 a-606 p of thescheduling matrices 602 a-602 d into the various time slot groups andexchanging the resource assignments associated with the various elements606 a-606 p.

As mentioned above, a scheduling matrix (e.g., scheduling matrices 300a, 300 b, 400 a, 400 b, 500 a, 500 b, 600 a, 600 b, 600 c, and 600 d)may be used to assign neighbor discovery signal resources to multiplewireless devices organized in a group. In some embodiments, multiplegroups of wireless devices may each be associated with one or morescheduling matrices. In these and other embodiments, the schedulingmatrices associated with a particular group of wireless devices may beassigned different time slots than the scheduling matrices associatedwith other groups of wireless devices. Therefore, the wireless devicesof one group of wireless devices may not transmit neighbor discoverysignals at the same time as wireless devices of the other groups ofwireless devices. Accordingly, the wireless devices may be able todiscover wireless devices included in other groups.

For example, a first scheduling matrix associated with a first group ofwireless devices may be assigned time slots “1” through “4” in a TDMAscheme. Therefore, the wireless devices of the first group may beconfigured to transmit their respective neighbor discovery signals atany one of the time slots “1” through “4”. Additionally, a secondscheduling matrix associated with a second group of wireless devices maybe assigned time slots “5” through “8” in the same TDMA scheme.Therefore, the wireless devices of the second group may be configured totransmit their respective neighbor discovery signals at any one of thetime slots “5” through “8”. Accordingly, the wireless devices of thefirst group may not transmit their respective neighbor discovery signalsat the same time that the wireless devices of the second group maytransmit their respective neighbor discovery signals.

The different groups may be assigned different time slots in any numberof ways and the assignment of time slots is not limited to the examplegiven above. For example, in some embodiments, one group may be assignedeven numbered time slots, while another group may be assigned oddnumbered timeslots instead of the manner described above, or any othersuitable assignment of time slots between groups may be performed.

Accordingly, in accordance to some embodiments described with respect toFIGS. 1-6, a wireless communication network may include one or moreaccess points configured to direct wireless devices to perform neighbordiscovery and may instruct one or more sets of wireless devices toparticipate in D2D communication. As described above, in someembodiments, the access points may determine the frequency and timetransmission schedules for transmission and/or reception of the neighbordiscovery signals by the wireless devices. Therefore, the access pointsmay direct the wireless devices to transmit and/or listen for neighbordiscovery signals at specifically assigned frequencies duringspecifically assigned time slots.

FIG. 7 is a flow chart of an example method 700 of wireless networkcontrolled initiation of D2D communication, arranged in accordance withthe present disclosure. The method 700 may be implemented, in someembodiments, by a wireless communication network, such as the network100 described with respect to FIG. 1. For instance, the access point 102and wireless devices 104 of the network 100 of FIG. 1 may be configuredto execute computer instructions to perform one or more operations forinitiating D2D communication between wireless devices 104, asrepresented by one or more blocks of the method 700. Althoughillustrated as discrete blocks, various blocks may be divided intoadditional blocks, combined into fewer blocks, or eliminated, dependingon the desired implementation.

The method 700 may begin at block 702, where a discovery channelresource may be assigned to a transmitting wireless device. Thetransmitting wireless device may accordingly be configured to transmit aneighbor discovery signal based on the discovery channel resource. Atblock 704, neighbor discovery signal information may be received from areceiving wireless device. The receiving wireless device may beconfigured to receive the neighbor discovery signal transmitted by thetransmitting wireless device and may determine the neighbor discoverysignal information based on the neighbor discovery signal as received bythe receiving wireless device. At block 706, the transmitting wirelessdevice and the receiving wireless device may be directed to participatein D2D communication with other based on the neighbor discovery signalinformation.

Therefore, the method 700 may be used to effectuate wirelesscommunication network controlled initiation of D2D communication. Oneskilled in the art will appreciate that, for this and other processesand methods disclosed herein, the functions performed in the processesand methods may be implemented in differing order. Furthermore, theoutlined steps and operations are only provided as examples, and some ofthe steps and operations may be optional, combined into fewer steps andoperations, or expanded into additional steps and operations withoutdetracting from the essence of the disclosed embodiments.

For instance, the method 700 may further include steps associated withconstructing proximity information based on the neighbor discoverysignal information and directing the transmitting wireless device andthe receiving wireless device to participate in D2D communication basedon the proximity information. Additionally, in some embodiments, theassigning of discovery channel resources may be done based on a PNDCHand associated scheduling matrices such as described above with respectto FIGS. 2 through 6D.

Returning to FIG. 1, in some embodiments, the transmitting wirelessdevice 104 a may transmit its neighbor discovery signals over the samefrequencies as, or frequencies close to, uplink and/or downlinkcommunications between the access point 102 (or other access points) andother wireless devices 104. Therefore, as mentioned above, in someembodiments, the network 100 may be configured to control the powerlevel of the neighbor discovery signals such that the neighbor discoverysignals may not substantially interfere with other wirelesscommunications.

In some embodiments, when the transmitting wireless device 104 a isconfigured to transmit its associated neighbor discovery signal overfrequencies associated with uplink communications, the access point 102and/or network controller 101 may determine the power of thetransmitting wireless device 104 a neighbor discovery signal based onone or more of a maximum transmission power of the transmitting wirelessdevice 104 a, interference experienced by communications between theaccess point 102 and other wireless devices 104, an uplink signalpathloss between the wireless device 104 a and the access point 102, acell specific power control adjustment associated with the number ofneighbor wireless devices discovered by the wireless devices 104 of thecell serviced by the access point 102 (e.g., the average number ofneighbors discovered by each wireless device 104 performing neighbordiscovery), an individual power control adjustment associated with thenumber of discovered neighbor wireless devices of the transmittingwireless device 104 a, among other things.

For example, the transmitting wireless device 104 a may not be able totransmit the neighbor discovery signal at a transmission power higherthan its maximum transmission power. Therefore, the transmission powerof the neighbor discovery signal may be associated with the maximumtransmission power of the transmitting wireless device.

Additionally, as mentioned above, when the neighbor discovery signal istransmitted on an uplink frequency, the neighbor discovery signal mayinterfere with uplink signals transmitted to the access point 102 fromother of the wireless devices 104. For example, the neighbor discoverysignal may interfere with the uplink signals such that the neighbordiscovery signal may raise the noise floor associated with the uplinksignals at the access point 102.

The amount of interference experienced by the uplink signals from theneighbor discovery signal may be associated with the signal power of theneighbor discovery signal. Additionally, the amount of interferenceexperienced by the uplink signals at the access point 102 from theneighbor discovery signal may be based on the power of the neighbordiscovery signal at the access point 102. Further, the power of theneighbor discovery signal as received by the access point 102 may relateto the pathloss between the transmitting wireless device 104 a and theaccess point 102. Therefore, in some embodiments, the pathloss betweenthe transmitting wireless device 104 a and the access point 102 may alsobe used as a reference power level for the neighbor discovery signal. Inthese and other embodiments, the power of SRS signals, physical uplinkshared channel (PUSCH) signals and/or physical uplink PUCCH signalstransmitted by the transmitting wireless device 104 a for reception bythe access point 102 may be used as reference power levels.

In some embodiments, the pathloss, SRS signal power, PUSCH signal power,and/or PUCCH signal power may each be applied with a weighting factorbased on the amount of interference experienced by the uplinkcommunications communicated to the access point 102 such that the amountof the pathloss, SRS signal power, PUSCH signal power, and/or PUCCHsignal power used as the reference power level may be adjusted based onthe interference. In some embodiments, the weighting factor may be anumber between “0” and “1” that may be determined by the network controlunit 101 and communicated to the access point 102 by the network controlunit 101.

The network control unit 101 may determine the weighting factor based oninterference that may be from the neighbor discovery signal,environmental factors, and/or other wireless signals (including otherneighbor discovery signals). When the uplink communications to theaccess point 102 experience a relatively high amount of interference(from the neighbor discovery signal and/or other factors) the networkcontrol unit 101 may set the weighting factor to be lower than when theuplink communications to the access point 102 experience a relativelylow amount of interference. Additionally, in some embodiments, thenetwork control unit 101 may set the weighting factor based on theinterference experienced by uplink communications intended for otheraccess points in instances when the neighbor discovery signaltransmitted by the transmitting wireless device 104 a may also interferewith the uplink communications intended for the other access points.

Further, as mentioned above, the access point 102 may adjust thetransmission power of the neighbor discovery signal based on a powercontrol adjustment associated with the number of neighbor wirelessdevices discovered by the transmitting wireless devices serviced by theaccess point 102 (e.g., the average number of neighbors discovered byeach wireless device 104 performing neighbor discovery by transmitting aneighbor discovery signal). When a transmitting wireless device, such asthe transmitting wireless device 104 a, transmits a neighbor discoverysignal, the number of wireless devices that may receive the neighbordiscovery signal (and thus may be discovered neighbors of the wirelessdevice transmitting the neighbor discovery signal) may be based on thetransmission power of the neighbor discovery signal. Therefore, theaccess point 102 may direct the transmitting wireless devices to adjustthe transmission power of their respective neighbor discovery signalssuch that the number of neighbor wireless devices discovered by at leasta majority of the transmitting wireless devices may be within a desiredrange (e.g., between 6 and 10). In some embodiments, the access point102 may make this determination based on the average number of neighborwireless devices discovered by each wireless device transmitting aneighbor discovery signal.

The access point 102 may also adjust the transmission power of thetransmitting wireless device 104 a based on the number of neighborsindividually discovered by the transmitting wireless device 104 a.Therefore, the access point 102 may also make individual poweradjustments for the transmitting wireless device 104 a such that thenumber of neighbor wireless devices discovered by the transmittingwireless device 104 a may be within the desired range.

In some embodiments the access point 102 may determine the neighbordiscovery signal power based on one or more of the followingexpressions:P _(NDS)=min(P _(max) ,α·PL _(C) +ΔP _(C) +ΔP _(WD));P _(NDS)=min(P _(max) ,α·P _(SRS) +ΔP _(C) +ΔP _(WD));P _(NDS)=min(P _(max) ,α·P _(PUSCH) +ΔP _(C) +ΔP _(WD)); andP _(NDS)=min(P _(max) ,α·PL _(PUCCH) +ΔP _(C) +ΔP _(WD))

In the above expressions: “P_(NDS)” may represent the determined powerof the neighbor discovery signal transmitted by the transmittingwireless device 104 a; “P_(max)” may represent the maximum transmissionpower of the transmitting wireless device 104 a; “a” may represent theweighting factor associated with the interference experienced by uplinkcommunications; “PL_(C)” may represent the pathloss between thetransmitting wireless device 104 a and the access point 102; “P_(SRS)”may represent the SRS signal power of an SRS signal transmitted betweenthe transmitting wireless device 104 a and the access point 102;“P_(PUSCH)” may represent the PUSCH signal power of a PUSCH signaltransmitted between the transmitting wireless device 104 a and theaccess point 102; “P_(PUCCH)” may represent the PUCCH signal power of aPUCCH signal transmitted between the transmitting wireless device 104 aand the access point 102; “ΔP_(C)” may represent the cell specific powercontrol adjustment described above; and “ΔP_(WD)” may represent theindividual power control adjustment associated with the transmittingwireless device 104 a, also described above.

Accordingly, in the first expression, the transmission power of theneighbor discovery signal of the transmitting wireless device 104 a maybe the lower value of the maximum transmission power of the transmittingwireless device 104 a or the sum of the pathloss multiplied by theweighting factor, the cell specific power adjustment and the individualpower adjustment for the transmitting wireless device 104 a. In thesecond expression, the transmission power of the neighbor discoverysignal of the transmitting wireless device 104 may be the lower value ofthe maximum transmission power of the transmitting wireless device 104 aor the sum of the SRS signal power multiplied by the weighting factor,the cell specific power adjustment, and the individual power adjustmentfor the transmitting wireless device 104 a. In the third expression, thetransmission power of the neighbor discovery signal of the transmittingwireless device 104 a may be the lower value of the maximum transmissionpower of the transmitting wireless device 104 a or the sum of the SRSsignal power multiplied by the weighting factor, the cell specific poweradjustment, and the individual power adjustment for the transmittingwireless device 104 a.

Accordingly, the above expressions may be used by the access point 102to set the transmission power level of the neighbor discovery signal ofthe transmitting wireless device 104 a when the transmitting wirelessdevice 104 a is configured to transmit the neighbor discovery signalover one or more frequencies associated with uplink communications. Whenthe transmitting wireless device 104 a is configured to transmit theneighbor discovery signal over one or more frequencies associated withdownlink communications, the access point 102 may determine thetransmission power of the neighbor discovery signal in a slightlydifferent manner, as described below.

When the transmitting wireless device 104 a is configured to transmitthe neighbor discovery signal over a downlink frequency, informationassociated with the interference experienced by downlink communicationsbetween the access point 102 (or other access points) and other wirelessdevices 104 may not be readily available. Accordingly, in theseembodiments, the power of the neighbor discovery signal may be based onthe maximum transmission power of the transmitting wireless device 104 aand may also be based on a cell specific transmission power associatedwith an estimated number of neighbor wireless devices that may bediscovered by each of the transmitting wireless devices within the cellserviced by the access point 102 when their neighbor discovery signalsare at the cell specific transmission power. Additionally, the power ofthe neighbor discovery signal when the neighbor discovery signal istransmitted over a downlink frequency may be based on an individualpower adjustment of the transmitting wireless device 104 a associatedwith the number of neighbor wireless devices that may be discovered bythe transmitting wireless device 104 a with its associated neighbordiscovery signal.

In these and other embodiments, the access point 102 may determine theneighbor discovery signal power based on the following expression:P _(NDS)=min(P _(max) ,P _(C) +ΔP _(WD))

In the above expression: “P_(NDS)” may represent the determined power ofthe neighbor discovery signal transmitted by the transmitting wirelessdevice 104 a; “P_(max)” may represent the maximum transmission power ofthe transmitting wireless device 104 a; “P_(C)” may represent the cellspecific power level described above; and “ΔP_(WD)” may represent theindividual power control adjustment associated with the transmittingwireless device 104 a, also described above. As indicated by theexpression, the transmission power of the neighbor discovery signal ofthe transmitting wireless device 104 a may be the lower value of themaximum transmission power of the transmitting wireless device 104 a orthe sum of the cell specific power level and the individual poweradjustment for the transmitting wireless device 104 a. Accordingly, theabove expressions may be used by the access point 102 to set thetransmission power level of the neighbor discovery signal of thetransmitting wireless device 104 a when the transmitting wireless device104 a is configured to transmit the neighbor discovery signal over oneor more frequencies associated with downlink communications.

Therefore, the access point 102 may determine the transmission power ofthe neighbor discovery signal in a manner as described above. Afterdetermining the transmission power of the neighbor discovery signal, theaccess point 102 may instruct the transmitting wireless device 104 a totransmit its neighbor discovery signal at the determined transmissionpower. In some embodiments, the access point 102 may instruct thetransmitting wireless device 104 a based on an RRC configuration.

Modifications may be made to the power control described above. Forexample, the access point 102 and/or transmitting wireless device 104 amay determine one or more parameters associated with determining andsetting the power of the neighbor discovery signal. Further, any numberof wireless devices 104 may be configured as transmitting wirelessdevices and the power level of each neighbor discovery signal associatedwith each transmitting wireless device may be adjusted in a manner asdescribed above. Additionally, one or more of the factors describedabove may be used to adjust the power of a neighbor discovery signaleven if the neighbor discovery signal is not transmitted on uplink ordownlink frequencies.

FIG. 8 is a flow chart of an example method 800 of power control of aneighbor discovery signal, arranged in accordance with the presentdisclosure. The method 800 may be implemented, in some embodiments, by awireless communication network, such as the network 100 described withrespect to FIG. 1. For instance, the access point 102, the networkcontrol unit 101, and/or the wireless devices 104 of the network 100 ofFIG. 1 may be configured to execute computer instructions to perform oneor more operations for controlling the power level of a neighbordiscovery signal, as represented by one or more blocks of the method800. Although illustrated as discrete blocks, various blocks may bedivided into additional blocks, combined into fewer blocks, oreliminated, depending on the desired implementation.

The method 800 may begin at block 802, where a maximum transmissionpower of a transmitting wireless device may be determined. Thetransmitting wireless device may be configured to transmit a neighbordiscovery signal to one or more receiving wireless devices. Therefore,the one or more receiving wireless devices may be discovered neighborwireless devices of the transmitting wireless device.

At block 804, a power level of the neighbor discovery signal may bedetermined. The power level of the neighbor discovery signal may bedetermined based on the maximum transmission power of the transmittingwireless device and a number of the discovered neighbor wirelessdevices.

Therefore, the method 800 may be used to determine a power level of aneighbor discovery signal. One skilled in the art will appreciate that,for this and other processes and methods disclosed herein, the functionsperformed in the processes and methods may be implemented in differingorder. Furthermore, the outlined steps and operations are only providedas examples, and some of the steps and operations may be optional,combined into fewer steps and operations, or expanded into additionalsteps and operations without detracting from the essence of thedisclosed embodiments.

For instance, in some embodiments, the method 800 may further includesteps associated with determining the neighbor discovery signal powerbased on at least one of a power level of a PUSCH signal transmittedbetween the transmitting wireless device and a wireless network accesspoint, a power level of a PUCCH signal transmitted between thetransmitting wireless device and the wireless network access point, apower level of an SRS signal transmitted between the transmittingwireless device and the wireless network access point, and an uplinksignal pathloss between the transmitting wireless device and thewireless network access point. Further, in these and other embodiments,the method 800 may further include steps associated with determining theneighbor discovery signal power level based on a number of neighboringwireless devices discovered by another transmitting wireless device.Also, the method 800 may include steps associated with determining theneighbor discovery signal power level based on interference experiencedby communications between another wireless device and an access point ofthe wireless communication network.

Embodiments described herein may be implemented using computer-readablemedia for carrying or having computer-executable instructions or datastructures stored thereon. Such computer-readable media may be anyavailable media that may be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation, suchcomputer-readable media may comprise tangible computer-readable storagemedia including Random Access Memory (RAM), Read-Only Memory (ROM),Electrically Erasable Programmable Read-Only Memory (EEPROM), CompactDisc Read-Only Memory (CD-ROM) or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any other storagemedium which may be used to carry or store desired program code in theform of computer-executable instructions or data structures and whichmay be accessed by a general purpose or special purpose computer.Combinations of the above may also be included within the scope ofcomputer-readable media.

Computer-executable instructions comprise, for example, instructions anddata which cause a general purpose computer, special purpose computer,or special purpose processing device to perform a certain function orgroup of functions. Although the subject matter has been described inlanguage specific to structural features and/or methodological acts, itis to be understood that the subject matter defined in the appendedclaims is not necessarily limited to the specific features or actsdescribed above. Rather, the specific features and acts described aboveare disclosed as example forms of implementing the claims.

As used herein, the term “module” or “component” may refer to softwareobjects or routines that execute on the computing system. The differentcomponents, modules, engines, and services described herein may beimplemented as objects or processes that execute on the computing system(e.g., as separate threads). While the system and methods describedherein are preferably implemented in software, implementations inhardware or a combination of software and hardware are also possible andcontemplated. In this description, a “computing entity” may be anycomputing system as previously defined herein, or any module orcombination of modulates running on a computing system.

All examples and conditional language recited herein are intended forpedagogical objects to aid the reader in understanding the presentdisclosure and the concepts contributed by the inventor to furtheringthe art, and are to be construed as being without limitation to suchspecifically recited examples and conditions. Although embodiments ofthe present disclosure have been described in detail, it should beunderstood that the various changes, substitutions, and alterationscould be made hereto without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A method comprising: determining a maximumtransmission power of a transmitting wireless device configured totransmit a neighbor discovery signal configured to be received by one ormore receiving wireless devices that are configured to receive theneighbor discovery signal; obtaining a number of previous neighborwireless devices previously discovered by another transmitting wirelessdevice, the previous neighbor wireless devices being discovered throughreception, by the previous neighbor wireless devices, of a previousneighbor discovery signal transmitted by the other transmitting wirelessdevice; determining, based on the number of previous neighbor wirelessdevices, a target number of receiving wireless devices that arediscoverable neighbor wireless devices of the transmitting wirelessdevice, the target number including a range of numbers; determining apower level of the neighbor discovery signal based on the maximumtransmission power of the transmitting wireless device and based on thepower level being such that the neighbor discovery signal is received bythe target number of receiving wireless devices; and directing thetransmitting wireless device to transmit the neighbor discovery signalat the determined power level.
 2. The method of claim 1, furthercomprising determining the power level of the neighbor discovery signalbased on interference experienced by a communication between anotherwireless device and a wireless network access point.
 3. The method ofclaim 1, further comprising determining the power level of the neighbordiscovery signal based on at least one of a Physical Uplink SharedChannel (PUSCH) power level of a PUSCH signal transmitted between thetransmitting wireless device and a wireless network access point, aPhysical Uplink Control Channel (PUCCH) power level of a PUCCH signaltransmitted between the transmitting wireless device and the wirelessnetwork access point, a Sounding Reference Signal (SRS) power level ofan SRS signal transmitted between the transmitting wireless device andthe wireless network access point, and an uplink signal pathloss betweenthe transmitting wireless device and the wireless network access point.4. The method of claim 3, further comprising using at least one of thePUSCH power level, the PUCCH power level, the SRS power level, and theuplink signal pathloss as a reference power level for the neighbordiscovery signal.
 5. The method of claim 4, further comprising applyinga weighting factor to at least one of the PUSCH power level, the PUCCHpower level, the SRS power level, and the uplink signal pathloss todetermine the reference power level, the weighting factor based oninterference experienced by an uplink communication between anotherwireless device and at least one of the wireless network access pointand another wireless network access point.
 6. The method of claim 1,further comprising communicating the power level of the neighbordiscovery signal based on a radio resource control (RRC) configuration.7. A processor configured to execute computer instructions to cause asystem to perform operations, the operations comprising: determining amaximum transmission power of a transmitting wireless device configuredto transmit a neighbor discovery signal configured to be received by oneor more receiving wireless devices that are configured to receive theneighbor discovery signal; obtaining a number of previous neighborwireless devices previously discovered by another transmitting wirelessdevice, the previous neighbor wireless devices being discovered throughreception, by the previous neighbor wireless devices, of a previousneighbor discovery signal transmitted by the other transmitting wirelessdevice; determining, based on the number of previous neighbor wirelessdevices, a target number of receiving wireless devices that arediscoverable neighbor wireless devices of the transmitting wirelessdevice, the target number including a range of numbers; and determininga power level of the neighbor discovery signal based on the maximumtransmission power of the transmitting wireless device and based on thepower level being such that the neighbor discovery signal is received bythe target number of receiving wireless devices.
 8. The processor ofclaim 7, wherein the operations further comprise determining the powerlevel of the neighbor discovery signal based on interference experiencedby a communication between another wireless device and a wirelessnetwork access point.
 9. The processor of claim 7, wherein theoperations further comprise determining the power level of the neighbordiscovery signal based on at least one of a Physical Uplink SharedChannel (PUSCH) power level of a PUSCH signal transmitted between thetransmitting wireless device and a wireless network access point, aPhysical Uplink Control Channel (PUCCH) power level of a PUCCH signaltransmitted between the transmitting wireless device and the wirelessnetwork access point, a Sounding Reference Signal (SRS) power level ofan SRS signal transmitted between the transmitting wireless device andthe wireless network access point, and an uplink signal pathloss betweenthe transmitting wireless device and the wireless network access point.10. The processor of claim 9, wherein the operations further compriseusing at least one of the PUSCH power level, the PUCCH power level, theSRS power level, and the uplink signal pathloss as a reference powerlevel for the neighbor discovery signal.
 11. The processor of claim 10,wherein the operations further comprise applying a weighting factor toat least one of the PUSCH power level, the PUCCH power level, the SRSpower level, and the uplink signal pathloss to determine the referencepower level, the weighting factor based on interference experienced byan uplink communication between another wireless device and at least oneof the wireless network access point and another wireless network accesspoint.
 12. A method of transmitting a neighbor discovery signal, themethod comprising: receiving, by a transmitting wireless device, a powerlevel of a neighbor discovery signal configured to be received by one ormore receiving wireless devices that are configured to receive theneighbor discovery signal, the transmitting wireless device beingconfigured to transmit the neighbor discovery signal, and the powerlevel of the neighbor discovery signal being determined by: obtaining anumber of previous neighbor wireless devices previously discovered byanother transmitting wireless device, the previous neighbor wirelessdevices being discovered through reception, by the previous neighborwireless devices, of a previous neighbor discovery signal transmitted bythe other transmitting wireless device; determining, based on the numberof previous neighbor wireless devices, a target number of receivingwireless devices that are discoverable neighbor wireless devices of thetransmitting wireless device, the target number including a range ofnumbers; and determining the power level of the neighbor discoverysignal based on a maximum transmission power of the transmittingwireless device and based on the power level being such that theneighbor discovery signal is received by the target number of receivingwireless devices.
 13. The method of claim 12, wherein the power level ofthe neighbor discovery signal is further based on interferenceexperienced by a communication between another wireless device and awireless network access point.
 14. The method of claim 12, wherein thepower level of the neighbor discovery signal is further based on atleast one of a Physical Uplink Shared Channel (PUSCH) power level of aPUSCH signal transmitted between the transmitting wireless device and awireless network access point, a Physical Uplink Control Channel (PUCCH)power level of a PUCCH signal transmitted between the transmittingwireless device and the wireless network access point, a SoundingReference Signal (SRS) power level of an SRS signal transmitted betweenthe transmitting wireless device and the wireless network access point,and an uplink signal pathloss between the transmitting wireless deviceand the wireless network access point.
 15. The method of claim 14,wherein at least one of the PUSCH power level, the PUCCH power level,the SRS power level, and the uplink signal pathloss is used as areference power level for the neighbor discovery signal.
 16. The methodof claim 15, wherein a weighting factor is applied to at least one ofthe PUSCH power level, the PUCCH power level, the SRS power level, andthe uplink signal pathloss to determine the reference power level, theweighting factor based on interference experienced by an uplinkcommunication between another wireless device and at least one of thewireless network access point and another wireless network access point.17. The method of claim 12, further comprising receiving the power levelof the neighbor discovery signal based on a radio resource control (RRC)configuration.